Table 3.

¹H NMR spectroscopic data (δ) for compounds 15 and 16^a (δ in ppm, J in Hz).

No.	15	16	No.	15	16
1	6.24 s	6.27 s	19	3.06 d (19.0), 2.35 d (19.0)	3.64 d (19.0), 2.60 d (19.0)
4	1.48 m	1.72 m	21	7.24 s	7.26 s
5	1.90 (overlapped)	2.48 m	22	6.26 s	7.28 s
6a	1.91 m	2.73 t (14.5)	23	7.37 s	7.38 s
6b	1.67 m	2.44 m
7	3.95 t (3.0)		28	0.87 d (7.0)	0.90 d (7.0)
9	2.68 d (6.5)	2.20 d (4.5)	29	0.80 d (7.0)	0.86 d (7.0)
11	4.57 td (9.0, 6.0)	4.34 m	30	1.32 s	1.63 s
12a	2.67 dd (13.5, 9.0)	2.80 dd (14.0, 8.5)	3′		7.16 m
12b	1.33 (overlapped)	1.69 dd (13.5, 6.5)
15	5.69 brd d (3.0)	6.28 brd s	4′		1.91 s
16a	2.55 ddd (15.5, 11.0, 2.0)	2.58 (overlapped)	5′		1.88 dd (7.0,1.5)
16b	2.48 ddd (15.5, 7.0, 3.0)	2.42 (overlapped)
17	2.87 dd (11.0, 7.5)	2.92 dd (11.0,7.0)	OAc	1.90 s
18	0.81 s	0.86 s

^aNMR data (δ) were measured at 500 MHz in CDCl₃ for 15 and 16.